diff --git a/reactos/include/ndk/rtltypes.h b/reactos/include/ndk/rtltypes.h
index 9aa41d95e5e..4f1e5338da1 100644
--- a/reactos/include/ndk/rtltypes.h
+++ b/reactos/include/ndk/rtltypes.h
@@ -138,7 +138,7 @@ Author:
      HEAP_CREATE_ALIGN_16           |                       \
      HEAP_CREATE_ENABLE_TRACING     |                       \
      HEAP_CREATE_ENABLE_EXECUTE)
-#ifdef C_ASSERT
+#ifndef __GNUC__
 C_ASSERT(HEAP_CREATE_VALID_MASK == 0x0007F0FF);
 #endif